This invention relates to an electric door opener with a keeper subject to the action of an armature and a magnet coil which is selectively positioned for releasing or locking a door latch.
A distinction exists between modes of operation for electric door openers, namely, fail safe or fail secure. In the fail safe mode, the door is unlocked unless energized whereas in the fail secure mode the door is locked unless energized. The two modes of operation have generally required two different basic constructions. The use of two different constructions resulted in increased costs for manufacture and stocking of said types.
Further, the structure of electric door openers are subject to a great deal of force when users open and shut such door normally let alone when someone actually attempts to force the door. Such forces can result in damage needing repairs which downtime can defeat the purpose of having the. electric door opener in the first place. Thus, there is a need to reduce the forces acting upon electric door opener structures.
A door opener with a transmission lever is disclosed in EP 279 878 A1. The function of this electric door opener is based on the fact that the transmission lever is held by a release lever armature in the swivelling area of a keeper until the release lever releases the transmission lever by the operation of a magnetic coil. With the aid of a spring , the transmission lever is brought out of the swiveling range of the keeper.
In addition, electric strike mechanisms of the prior art are generally composed of a face plate having the housing for the mechanism projecting rearwardly therefrom. To accommodate such mechanisms, the prior art device require cutting out the doorjamb to install.
U. S. Pat. No. 5,788,295 entitled xe2x80x9cElectric Door Opener with Multiple Position Armature Permitting Different Operation Modesxe2x80x9d which issued on Aug. 4, 1998 to Fuss et al. discloses an electric door opener with a transmission lever actuable by a release lever and a magnetic coil. The release lever is adjustable by position to release or lock a keeper through a transmission lever. A selector device is provided to switch the system between fail safe and fail secure modes.
None of the known prior art disclose the device set forth herein.
It is an object of this invention to provide an electric door opener which can be used in either a fail safe or fail secure mode.
It is a further object of this invention to strengthen the locking mechanism of an electric door opener while, at the same time reduce the forces acting upon the structure thereof.
It is still another object of the invention to provide a surface mount electric door opener which eliminates the need to cut out a door jamb to install.
Further objects and advantages of the invention will become apparent as the following description proceeds and the features of novelty which characterize this invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.